This is an I2C based light sensor.
BH1750FV Ambient Light Sensor Module GY-30 for Arduino & Raspberry Pi

The BH1750FVI sensor to measure the ambient lighting level. BH1750FVI is a calibrated digital light sensor IC that measures the incident light intensity and converts it into a 16-bit digital number. It can measure ambient light intensity ranging from 0 to 65535 Lux (L). The Lux is an SI unit for illuminance and is equal to one lumen per square meter. The BH1750FVI sensor directly gives output in Lux. The spectral response function of the sensor is approximately close to that of the human eye. The sensor output can be accessed through an I2C interface. The 7-bit I2C address is 0×23 if the ADDR pin is grounded, or 0x5C if ADDR is tied to VCC.

Features:
Ambient light sensor IC on easy to interface module
16 Bit Resolution
Direct LUX output
I2C Interface